Schizandra and Cariprazine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 16, 2026 · Source data updated Jul 16, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cariprazine
Schizandra
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Here's what's going on. Your body uses an enzyme called CYP3A4 to break down cariprazine (Vraylar). Schizandra can slow that enzyme down. When the enzyme works slower, more cariprazine and its active byproduct build up in your body. That can mean stronger effects and more side effects, like drowsiness, restlessness, dizziness, or shakiness.
The good news is this is very manageable. If you take both, your care team can lower your cariprazine dose and keep a closer eye on how you're feeling. Please don't stop or change anything on your own. Just let your pharmacist or doctor know you're taking Schizandra so they can tailor your dose safely.
Mechanism: Schizandra is a moderate CYP3A4 inhibitor; cariprazine is a CYP3A4 substrate. Inhibition reduces clearance, increasing exposure to cariprazine and its long-acting active metabolite didesmethylcariprazine (DDCAR).
Effect/direction: Increased cariprazine/DDCAR AUC, raising risk of dose-related adverse effects (EPS, akathisia, somnolence). Evidence: probable; onset unspecified but prolonged given DDCAR half-life.
Management (per labeling for moderate 3A4 inhibitors):
- Reduce cariprazine dose per indication-specific guidance (e.g., stable 1.5/3 mg once daily to 1.5 mg every other day; 4.5/6 mg once daily to 1.5 mg once daily).
- Titrate to clinical response and tolerability.
- On inhibitor discontinuation, cariprazine dose may need upward adjustment.
What happens
Increased cariprazine and its major active metabolite (didesmethylcariprazine (DDCAR)) exposure
Interaction Deep Dive
Giving cariprazine (which is metabolized by CYP3A4) together with a moderate CYP3A4 inhibitor can raise the levels of both cariprazine itself and its active metabolite, didesmethylcariprazine. If cariprazine is being started in a patient already on a moderate CYP3A4 inhibitor for schizophrenia or bipolar mania, the recommended starting dose is 1.5 mg orally every other day, with a possible increase to 1.5 mg orally every other day, if needed, guided by clinical response and tolerability. For those on a moderate CYP3A4 inhibitor for bipolar depression or as adjunctive therapy in the treatment of MDD, the dose is 1.5 mg orally every other day. When a moderate CYP3A4 inhibitor is added to a patient already stabilized on cariprazine, the following applies: if the patient is currently taking 1.5 or 3 mg once daily, the cariprazine dose should be changed to 1.5 mg orally every other day upon starting the moderate inhibitor. If the patient is currently taking cariprazine 4.5 or 6 mg once daily, the dose should be changed to 1.5 mg orally once daily upon starting the moderate inhibitor. Should the moderate CYP3A4 inhibitor be stopped, the cariprazine dose may require an increase based on clinical response and tolerability1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of cariprazine
How to manage this interaction
What your care team may do:
- Adjust your cariprazine dose so the amount in your body stays in a safe range. The exact dose will be individualized by your care team based on your indication and current dose.
- Monitor you more closely for side effects like restlessness, muscle stiffness, tremor, or drowsiness.
- Revisit your dose if you later stop Schizandra, since cariprazine may need to be increased again.
What you should do: Keep taking both exactly as prescribed unless told otherwise, and tell your pharmacist or prescriber that you take Schizandra (and any supplements). Report new or worsening side effects.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In drug interaction investigations, giving cariprazine 1.5 mg/day together with erythromycin (a moderate CYP3A4 inhibitor) 500 mg twice daily for 21 days led to an increase in cariprazine AUC (0 to 24 hours) and Cmax of roughly 50% 1. In a single study that enrolled only White males taking cariprazine 1.5 mg/day and erythromycin 500 mg twice daily (n=40), AUCs rose by 38% (cariprazine), 11% (desmethylcariprazine, an active metabolite), and 60% (didesmethylcariprazine, an active metabolite), while Cmax increased by 34%, 16%, and 62%, respectively. Tmax was unaffected by concurrent administration of erythromycin 2.
Common questions
Can I take Schizandra and Cariprazine together?
Schizandra can raise cariprazine levels and increase side effects, so your care team will likely lower and individualize your cariprazine dose and watch you more closely. Keep taking both as prescribed and tell your pharmacist about the supplement. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Schizandra and Cariprazine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Schizandra and Cariprazine interaction managed?
What your care team may do: Adjust your cariprazine dose so the amount in your body stays in a safe range. The exact dose will be individualized by your care team based on your indication and current dose. Monitor you more closely for side effects like restlessness, muscle stiffness, tremor, or drowsiness. Revisit your dose if you later stop Schizandra, since cariprazine may need to be increased a… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Schizandra or Cariprazine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: VRAYLAR(R) oral capsules, cariprazine oral capsules. AbbVie Inc. (per FDA), North Chicago, IL, 2024. DailyMed
- Szabo M, Hujber Z, Harsanyi J, et al: Coadministration of cariprazine with a moderate CYP3A4 inhibitor in patients with schizophrenia: implications for dose adjustment and safety monitoring. Clin Pharmacokinet 2024; 63(10):1501-1510. PubMed
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